0² (Zero-Two) is the mastermind and Final Boss behind the events of Kirby 64: The Crystal Shards, fought in the Dark Star. It is a zombified version of Zero from Kirby's Dream Land 3, but it is not the same character. Collecting all Crystal Shards before the Miracle Matter battle is required to meet 0², or it will enter the False Ending.
0², judging by its name and appearance, appears to be the same being from Kirby's Dream Land 3. However, there are differences.
First, 0² has a halo and a pair of wings, which may mean Zero and 0² are the same eyeball. Also, 0² has a cactus-like appendage on its underside, as well as a bandage under its halo. This is where its eye was before Zero tore it out in a last-chance attempt to get rid of Kirby in Kirby's Dream Land 3. 0² also releases blood, when its new eye is hit, making 0² and Zero the most maturely depicted bosses in the whole series. Its halo and wings may suggest that 0² is a reincarnation or angelic form of Zero.
0² has only two forms of attack: firing explosive orbs from its eye, and releasing green gas when its underside is out.
0² does not start out directly damageable; it must be stunned by striking its eye. Then, Kirby and Ribbon can fly to its halo and shoot it until it vanishes and the bandage is struck. From there, either the wings or the "tail" can be hit.
If the wings are shot, they slow 0² to the point that the halo can be struck without the need for stunning 0². However, the "tail" must be attacked to damage 0². After a while, the "tail" retracts, and after enough damage is done, 0² explodes with Dark Star.
If the player pauses the game in Dark Star, the "Try Again" option (which functions the same as "Quit" in other games) will be replaced by "Tough It Out!" (がんばる in Japanese), which functions the same as selecting the "Continue" button, so the player cannot quit the battle.
- Main article: 0² Battle
- 0² appears in the Celebration Pictures: "Chasing Our Dreams" and "Bad Boss Brothers" in Kirby Star Allies.
- If the ZL or ZR buttons are pressed during the fight in the Virtual Console version, the camera will rotate.
- Although it may be possible to construe the blood that splurts from Zero and 0² as merely red energy blobs, both the ending credit illustration of 0² in Kirby 64: The Crystal Shards and the game's ESRB rating in Kirby's Dream Collection confirm it as blood.
- It takes 30 hits to stun 0² via the eye, and an additional 10 hits to destroy 0²'s halo to show his vulnerable "tail".
- Before the fight with 0² begins, the boss briefly shows a strange less-threatening face, with two black dots for eyes and the closed main eye serving as a smiling mouth. Why it briefly looks like this before changing to its look during the fight is unknown.
- The background for this boss is the same as the pool on the ground of The Divine Terminus in Heroes in Another Dimension once three dimensions are cleared and when fighting Morpho Knight in Soul Melter of The Ultimate Choice as Adeleine & Ribbon, Dark Meta Knight and Daroach.